Cover Crops are an important part of any healthy cropping
system. What is a cover crop? A cover crop is a crop that is grown to maintain
and improve soil fertility, water quality, as well as to help manage pests and
diseases. Cover crops are often planted after a crop grown for harvest has been
harvested, with the intention of improving soil tilth, reducing soil erosion,
recycling nutrients such as nitrogen, and bringing other benefits to the farm.
Using cover crops as part of your regular crop rotation plan
can increase the yield of the following cash crop. One of the most advocated uses of cover crops
is for erosion control during the winter, after the cash crop has been removed.
The type of cover crop you select is dependent upon several
factors, including how you will seed it, the weather conditions, and how you
will kill the crop.
Types of Cover Crops:
Legumes
Legumes are plants in the pea family. Legume cover crops are
those can “fix” nitrogen, meaning that they reduce the need for nitrogen fertilizer
by using root nodules to naturally fix nitrogen into a form that is usable by
the plant. They can also increase the organic matter in the soil. Legumes
should be planted early enough to allow for adequate growth before the first
killing frost, roughly six weeks.
Non-legumes
Non-legumes include cereals (rye, wheat, oats, triticale),
forage grasses (annual ryegrass), and broadleaf species (buckwheat, brassicas).
These are best for scavenging nutrients, erosion control, weed control, and
adding organic matter from residue. Non-legumes are best in a field that has
excess nutrients, particularly nitrogen. They can scavenge 150 pounds of
nitrogen per acre.
In organic farming, cover crops are critical way in which
nutrients are added to the soil. In addition to adding nutrients, they provide
organic matter which Is a more long-term goal when considering soil health. Cover
crop may be left as a mulch or incorporated. If cover crop is incorporated into
the soil before planting the main crop, it is called a green manure.
With some crops like pumpkins, a cover crop is killed and
the pumpkins are planted into the residue, which is used as a way to conserve
water, control weeds, and can even keep the pumpkins cleaner by reducing
splashing of dirt and mud.
 |
| Pumpkins being planted into a killed oat cover crop. |
Consult Virginia Cooperative Extension for more information on selecting appropriate cover crops for your farming operation. No matter which cover crop you decide to utilize, you should devote as much attention to them as you do your cash crops to prevent failure and problems throughout your cropping system.
Sources:
https://www.sare.org/Learning-Center/Topic-Rooms/Cover-Crops
http://www.tolweb.org/notes/?note_id=3920
https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1043183.pdf
